I am sure there is something not quite right about either translation. Is there a basis for translating "honesta" into "lawful"?

"The right, moreover, and honest (dignified? worthy?) ordering of the birth of offspring"?

The Latin honestum is a pain to render in English. The closest use of its English derivative is when we say something like "an honest good"

Honestum is contrasted to utile and delectabile. The utile bonum, mean the useful good, and the delectabile is the pleasing good. Honestum signifies what is good in itself. You may render it virtuous, as it is some desired for its own sake and perfective of itself and not (merely) as means to another. Respectable is another choice, but that can be misleading

I would render it if I was trying to be hyper literal "{Moreover} the right and honorable ordering of future offspring to be born"

Note how the gentive subject of ordinatio is not births, but the offspring (prolis) who will be born (nasciturae). Not, perhaps that relevant here.

Could honestum be rendered as lawful or licit? I suppose it could, but in doing so you lose much of the sense of the word. Something can be licit but not honestum (as what is lawful but not expedient)